Kubota L4610 electrical problem (need help please)

[Kubotajoe99]

My L4610 won't charge my battery. About 6 months ago the alternator went out and I took my tractor to the local mechanic and he ordered and replaced the alternator. All worked fine for 6 months, then after using my tractor for a couple of hours the other day, I turned it off and tried to start it again within a couple of minutes and the battery was dead. I was able to jump start it take it back to the mechanic. He replaced the alternator again (2nd one in 6 months). After getting it back from the mechanic yesterday, I used it for about 2 to 3 hours and turned it on and off 5 or 6 times, then one time it was totally dead again. The battery is 2 years old and will take a charge and tested good. The mechanic said I need to have the RPMs at 2000 to charge the battery and that it could charge as low as 12.5 volts on a diesel tractor. I'm only seeing about 12.6v at the battery at 2000 rpm. At an idle the voltage at the battery is about 11.9 to 12v. The alternator model is 12179N. Is the voltage at the battery to low? Is that the correct alternator? Is there a separate voltage regulator or is that inside the alternator? Any help would be greatly appreciated.

 

[grsthegreat]

Did you have the battery bench tested under 50% load?. I hardly run my tractor at 2000 rpm….usually at 1800 unless im moving dirt. Mine always charges.

when it refuses to start, is it completely dead or does it try to rurn over slowly. You could have bad battery cables or bad grounding issues going on.

 

[Kubotajoe99]

I'm not sure how the battery was tested, probably not a rigorous test. I also don't normally run at 2000 RPM. I've owed that tractor for 20 years and usually run between 1400 and 1500 RPM and never had a charging problem until 6 months ago. I'm thinking it might be the wrong alternator, a bad battery, or maybe glow plugs draining the battery?? When it won't start, it is totally dead. Jump starts from car easily.

 

[Root Cause]

I just had an electrical issue. It is frustrating. If you are waiting for service, put your frustration into something that costs nothing and might help.

Get some wrenches, sandpaper, and dielectric grease and clean up both ends of the positive and negative cables.
It might be that you have more than one issue and you get lucky. At the least, you have eliminated corrosion as a potential problem.

I found corrosion on the positive terminal, cleaned it up and it ran fine that day. Then had more issues the next week. Turned out to be more corrosion hiding under some other positive wires that were cobbled together and spliced to the positive terminal behind the breather.

While I was doing this, I installed a quick connection to the terminals to make it easier to plug in the battery tender this winter.



Good luck.

 

[Roadworthy]

If your terminals aren't making good contact your alternator may not charge the battery. Begin by charging the battery fully, then have it load tested. That will confirm the battery is good. Before reinstalling clean the terminals thoroughly as well as the cable ends. Connect cables securely to the battery. If you can move them around they're not secure. Follow the ground lead to the frame. Clean and tighten there. Now start the tractor and with it set to about 1500 rpm check the voltage at the battery. You should see around 13.5 to 14.5 volts. While the tractor is running you can check the voltage at the glow plugs. It should be zero. If it's ten or eleven volts your problem is with the glow plug controller. There should never be voltage there with the key off.

 

[rScotty]

Answers first. Explanations only if you want them.

Yes the system should charge fully at a high idle.... say over 11/1200 rpm. A voltmeter across the battery terminals at 14/1500 RPM will show between 13 and 14 volts DC - but only if the whole system is good. We need to eliminate some things.

Sure, the glow plugs could be the culprits. That's a nice piece of diagnosis. So open the hood and disconnect the wires to the glow plugs..or pull the fuse that activates them. Anything to make sure they are off.

We can figure this out if you want to take a few days to actually know what is happening.

First of all the battery. Is it a wet cell or an AGM. Do you have a "smart charger" & digital voltmeter? Is the digital voltmeter a VOM type that also measures continuity and resistance and can distinguish between AC and DC? We might need those abilitys later....not now.

First, we do the battery. Disconnect both battery leads from the battery.

Now you have a a choice. Taking the battery out and over to the bench is best because you can see the cables better so you can wiggle and inspect them. Look for an internal break in both cables. My Kubota had an internal break half way down the negative cable - I liked to never found it. Also scrape off all the corrosion down to bright metal, and specifically look for corrosion where the neg. bolts to the frame.

Do NOT get the acid salts on your good blue jeans.. If you mess up, use baking soda and water to kill the acid.

OK. Before doing anything, measure the voltage of the discharged battery.
Now hook it up to charger at about 4 to 8 amps overnight. No more amps than that, or you can get overheating and not as good a charge. When you turn the charger on, check across the terminals of the battery with your voltmeter to prove to yourself that the charger is supplying somewhere between 13 and 14 volts to the battery. Charge it overnight. Take it off the charger and let it set for at least an hour. Measure the battery voltage again and make a note of it. If it is less than 12.7 volts, put it back on the charger for all day and then measure again.

If 12.7 or over, the battery is probably good, but we need to let it just sit for 24 hours and measure it again. It should still be above 12.5 volts, preferably 12.6.

If it is a bad battery you will see the voltage slowly fall over the next few days just from sitting there not even hooked up. It will drop to the the 11 volts or less. The loss in voltage is caused by internal current flow from a buildup of sulfates on the plates.

rScotty

 

[Kubotajoe99]

Thank you Roadworthy for the advice. I will do as you suggest and get the battery checked out and clean/tighten cables. I haven't ever checked out the glow plugs so I'll have to find out where they are and which terminals to check. Thanks again.

 

[ns_in_tex]

If your terminals aren't making good contact your alternator may not charge the battery. Begin by charging the battery fully, then have it load tested. That will confirm the battery is good. Before reinstalling clean the terminals thoroughly as well as the cable ends. Connect cables securely to the battery. If you can move them around they're not secure. Follow the ground lead to the frame. Clean and tighten there. Now start the tractor and with it set to about 1500 rpm check the voltage at the battery. You should see around 13.5 to 14.5 volts. While the tractor is running you can check the voltage at the glow plugs. It should be zero. If it's ten or eleven volts your problem is with the glow plug controller. There should never be voltage there with the key off.

Like Roadworthy said, engine 1/2 throttle, should have at least 13 volts at battery. If not, check between battery ground post (actual post, not the clamp) and a metal portion of tractor frame. any volts above 0 equals a poor ground connection somewhere. Check between battery ground post and battery ground clamp. If volts above 0, it is a poor connection at cable clamp. Move around until you get a reading on either side of a specific connection. That is likely the poor connection that needs cleaning or replacing.

This works the same on both + & - wires. When meter probes are on either side of a poor connection, you will get a reading. When all is good, you will get 0 volts.

 

[Kubotajoe99]

Answers first. Explanations only if you want them.

Yes the system should charge fully at a high idle.... say over 11/1200 rpm. A voltmeter across the battery terminals at 14/1500 RPM will show between 13 and 14 volts DC - but only if the whole system is good. We need to eliminate some things.

Sure, the glow plugs could be the culprits. That's a nice piece of diagnosis. So open the hood and disconnect the wires to the glow plugs..or pull the fuse that activates them. Anything to make sure they are off.

We can figure this out if you want to take a few days to actually know what is happening.

First of all the battery. Is it a wet cell or an AGM. Do you have a "smart charger" & digital voltmeter? Is the digital voltmeter a VOM type that also measures continuity and resistance and can distinguish between AC and DC? We might need those abilitys later....not now.

First, we do the battery. Disconnect both battery leads from the battery.

Now you have a a choice. Taking the battery out and over to the bench is best because you can see the cables better so you can wiggle and inspect them. Look for an internal break in both cables. My Kubota had an internal break half way down the negative cable - I liked to never found it. Also scrape off all the corrosion down to bright metal, and specifically look for corrosion where the neg. bolts to the frame.

Do NOT get the acid salts on your good blue jeans.. If you mess up, use baking soda and water to kill the acid.

OK. Before doing anything, measure the voltage of the discharged battery.
Now hook it up to charger at about 4 to 8 amps overnight. No more amps than that, or you can get overheating and not as good a charge. When you turn the charger on, check across the terminals of the battery with your voltmeter to prove to yourself that the charger is supplying somewhere between 13 and 14 volts to the battery. Charge it overnight. Take it off the charger and let it set for at least an hour. Measure the battery voltage again and make a note of it. If it is less than 12.7 volts, put it back on the charger for all day and then measure again.

If 12.7 or over, the battery is probably good, but we need to let it just sit for 24 hours and measure it again. It should still be above 12.5 volts, preferably 12.6.

If it is a bad battery you will see the voltage slowly fall over the next few days just from sitting there not even hooked up. It will drop to the the 11 volts or less. The loss in voltage is caused by internal current flow from a buildup of sulfates on the plates.

rScotty

Thank you for the help! I will figure out how to disconnect the glow plugs and eliminate that from the potential problems.

The battery is a wet cell. My charger is pretty old. I've only got two settings for amperage, 2 amp or 15 amps. Will that work? I do have a digital voltmeter with continuity and resistance measurement and AC and DC settings.

 

[Kubotajoe99]

Like Roadworthy said, engine 1/2 throttle, should have at least 13 volts at battery. If not, check between battery ground post (actual post, not the clamp) and a metal portion of tractor frame. any volts above 0 equals a poor ground connection somewhere. Check between battery ground post and battery ground clamp. If volts above 0, it is a poor connection at cable clamp. Move around until you get a reading on either side of a specific connection. That is likely the poor connection that needs cleaning or replacing.

This works the same on both + & - wires. When meter probes are on either side of a poor connection, you will get a reading. When all is good, you will get 0 volts.

Thanks for the help! I will definitely do as you suggest. I've got a DC mV setting on my volt meter so I should be able to see it if that is the problem.